1. Field of the Invention
The present invention relates to photogrammetry. More specifically, the present invention relates to methods and apparatus for improving the resolution of charge coupled device (CCD) cameras used in photogrammetric applications.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
2. Description of the Related Art
Photogrammetry involves the use of aerial photography to produce maps and charts. Generally, photogrammetry works on the principle of stereo pairs in that an area is photographed from two different camera positions. The area of common coverage in each photograph is called the stereoscopic overlap. This area offers the means to determine the depth of a particular scene.
Each photograph may be considered a record of the various light rays or intensities which travel from the object viewed and are typically registered on photographic film. The intersection of corresponding light rays from each photograph provides information on the 3-dimensional aspects of the terrain.
Thus, traditional data acquisition in the generation of 3-D databases is in the form of photography. However, there are certain limitations associated with the use of conventional photographic techniques in photogrammetric applications. For example, the production of digitized visual databases from photographs is somewhat costly and time consuming. In addition, the quality of the visual data is limited by the grain size of the photographic film. Also, such data is often not up to date, requires time consuming film processing and needs to be extensively processed in order to be put in digitized form.
Video data is often more current and in the case of CCD cameras is in digitized form. Hence, for photogrammetric applications a CCD camera would be quite useful. However, the resolution of standard CCD camera data is limited by the size of individual pixels of the CCD chip.
Thus, there is a need in the art for a more efficient technique for generating high resolution photogrammetric image data. Particularly, there is a need for a technique for improving the resolution of a CCD camera in a photogrammetric application.